Trailer line control apparatus



April 28,'1953' T.- H. AFFLEcK 2,636,576

` TRAILER LINE CONTROL APPARATUS Filed Feb. 2, 194e 2 SHEETS-SHEET l TRAILER 3/ TRUCK l N. 3mm

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1". H. AFFLECK` -2',636,576 TRAILER LINE CONTROL APPARATUS Filed Feb. 2, 1948 2 SHEETS-SHEET 2 Z6 i 6 61 65' 6g Z3- o 66 ze] 64.

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the trailer brake when Patented Apr. 28, 1953 2,636,57 6 TRAILER LNE CONTROL APPARATUS Theodore Hubbard Aieck, North Hollywood, Calif., assigner to Homer T. Scale, Inc., Los Angeles, Calif., a corporation of California Application February 2, 1948, Serial No. 5,885

. 10 Claims. (Cl. 18S-3) AThis invention relates to atrailer line control apparatus intended for use in connection'with lines leading from a truck to a trailer. It is a general object of the present invention to provide an apparatus automatically shutting off both lines leading from a truck to a trailer, so that should either o f these lines break or become uncoupled, the supply of compressed air in the truck tank will be prevented from escaping to the atmosphere, and the trailer brakes will be applied.

In the operation of the brakes on a trailer attached to a truck there are two -lines leading -from the truck to the trailer. One or" these lines is known as the emergency line and is normally intended to be under air pressureat all times, and is the supply line from the truck tank to the trailer tank through the trailer relay emergency valve mechanism. The other line goes from the control valve on the truck (operated by the brake lever) to the relay'emergency valve on the trailer, and this line is only charged with air when an application of the brakes is to be made.

In the past, when the emergency line became uncoupled or ruptured so as to lose pressure, the trailer relay valve mechanism has been designed to'cause an emergency application of the trailer brakes. This will result in stopping the truck and trailer, provided the truck and trailer are hitched together; however, should the trailer break away from the truck, the breaking of the emergency line'has the eiect of rapidly exhausting all air pressure from the truck, so that the truck has no air pressure to apply the'truck brakes.

By means of the valve mechanism of the pres- 'ent invention means are provided by which the loss of pressure in the emergency line, through lrupture of this line, will automatically shut the `-emergency line ofi from the source of'air pressure on the truck, whereby the truck operator will retain a source of pressure -for setting the truck brakes. This operation is eiectedvwithout interfering with the usual vactionof the trailer relayr valve mechanism in automatically setting the emergencyv line is broken. 'I e 4Another cause of 'accidents' in operating a truckand trailer arises when the service line becomes ruptured or uncoupled while the emergency line remains connected. In such a case the trailer brakes are not applied, and there is no indication on the truck that such a service line vis ruptured. When the truck driver attempts to stophe -is unable to set the trailer. brakes, and, moreover, the operation of the brake valve connects the source of pressure on the truck to the ruptured service lines, so'that the air pressure on the truck is rapidly exhausted interfering with the operation of truck brakes.

By means of the present invention a device is provided by means of which the rupture of a service line will cause application of the trailer brakes, and, moreover, prevent the source of pressure on the truck from being exhausted. By means of the present invention, on severing of the service line, the driver retains full pressure in the truck for setting the truck brakes, and upon applying the brakes the service line is closed and the emergency line drained of air pressure which causes the trailer brakes to go into emergency.

The valve apparatus of the present invention, together with various further objects and advantages of the invention, will be fully understood from the following description of the preerred form of the invention. For this purpose, a preferred example of the invention is described in connection with the accompanying drawings, in which:

Figure 1 is a somewhat diagrammatic View illustrating the complete apparatus for actuating trailer brakes from a truck.

Figure 2 is an enlarged section of the loading valve.

Figure 3 is an end view of the control appara-tus, with certain valve parts in section, on the line 3 3 of Figure 4.

Figure 4 is a vertical section of the control apparatus substantially on the line 4-4 of Fig- Figure 5 is a vertical section through the trailer relay valve apparatus.

Referring rst to Figure 1 of the drawings, for the purpose of illustration, I have shown somewhat diagrammatically the control apparatus of the present invention in connection with a substantially complete apparatus for controlling trailer brakes. In the drawings, l represents an air compressor by means of which the usual tank 2 on the truck is supplied with air pressure. From the tank 2 a service line 3 extends to the control apparatus 4. This service line 3 is diagrammatically indicated as provided with a valve 3a, which is normally operated by the brake pedal of the truck, or by hand, and is movable to a position in which it connects line 3 with tank 2, and the other position, in which it shuts oi tank 2 from line 3, and at `the same time vents line 3 to the atmosphere. In normal practice of operating trailer brakes, the line 3` leads directly to a'relay` emergency valve positioned on the trailer, but in the case of the use of the apparatus of the present invention, the service line connecting the truck tank 2 and the relay emergency valve 5 is broken at the first portion 3 leading to the control apparatus, from which, as hereafter described, the second portion 2 of a service line leads to the relay emergency valve apparatus. It is also a conventional practice to provide a second line 1 leading from the truck tank 2 to the relay emergency valve 5, which is the so-called emergency line. In the case of the present invention, this emergency line is broken for the insertion of the control aparatus 4, 3 being the continuation of the emergency line to the relay valve mechanism from the control apparatus 4.

On the trailer there is provided the usual trailer tank 9 connected by the line I to the relay emergency valve mechanism 5, and from the relay emergency valve mechanism 5 there leads lines I I and I2, which connect with the brake cylinders I3 and I4 of the trailer.

Now referring more particularly to Figure 4 of the drawings, the control apparatus of the present invention includes a small tank I5, which is normally intended to be charged with air under pressure from the truck tank 2. As illustrated, this tank I5 has substantially cylindrical side walls IS, which are integral with an end wall I1 at the right, as viewed in the iigure. This end wall I1 is shown bowed inwardly somewhat to facilitate, as hereafter described, the mounting of a relay diaphragm. The left end of the tank I3 is closed by the cap member I8 held in position by bolts i9.

The cap member I3 has an opening 26 into which is threaded a hollow connector 2l, which serves as a connection and a mounting for a valve casing 22. The valve casing 22 is indicated as having a detachable lower plate 30, held in position by bolts 3l and packing 32. The plate 30 is made separate from the body of the casing merely for convenience in forming the casing. The valve casing 22 has a passage 23 which is connected to the emergency line portion 1, so as to normally be under the full pressure of the truck tank 2. From the passage 23 a bore 24 leads to a passage 25 which connects with the port 26 which leads through the hollow connector 2|, In the passage 25 is indicated a valve member 21, which has a packing 28 adapted to in one position close port 24. This valve member 21 is provided with a packing ring 23. Accordingly, whenever the valve member 21 is in the position shown in Figures 3 or 4, the small tank I5 will be maintained under the same pressure as the truck tank 2.

Attached to the casing 22 is a supplemental casing member 33, and within said supplemental casing member 33 and the casing 22 is mounted a movable means which includes a piston member 34, which has an enlarged upper part sealed to a cylindrical bore of the supplemental casing 33 by the sealing ring 35, and a reduced lower portion 33 sealed to a reduced bore by the sealing ring 31. A passage 33 leads through the enlarged end or" the piston 34 to discharge between the enlarged and smaller portions of the piston, there being a resilient band 33 which operates as a check Valve. From the space between the enlarged and smaller portions of the piston 34 there is a passage 40 through the supplemental casing 33 for the flow of air. A rod 4I is attached to the piston 34 and carries at its lower end a, plug 42. There is also provided a valve member 43 which is movable relative to the piston 34, andk is guided within the cylindrical bore of the supplemental casing 33 and sealed thereto by the sealing ring 44. A spring 4t normally urges the valve member 43 and piston 34 apart. The valve member 43 has a packing 46 to assist the same in making a seat on an annular ridge 41 of the casing 22. This packing is also adapted for engagement with the plug 42, so that the plug 42 is adapted to close an exhaust passage 41EL which extends axially through the valve member 43 and communicates with the exhaust port 43. The port 23 communicates with a space 49 surrounding the valve member 43, from which flow of air may pass if valve 43 is removed from its seat against ridge 41 through the bore 50 to underneath the valve piston 21.

The upper end of the supplemental casing 33 is closed by a plug 5 I, to which is connected a line 52, which leads to the three-way connection 53, and thereby establishesl communication with the interior of the small tank l5.

In normal operation the valve means Gas.- ings 22 and 33 operate as follows. When there is pressure in the small tank I5 this pressure forces the piston member 34 downwardly causing the valve member 43 to engage its seat 41, spring 45 being compressed and plug 42 being moved from seat 4B. In this Position the valve means shuts off the flow of fluid from port 23 by the valve 46 to below the piston valve member 21. The air underneath the piston valve member 21 is exhausted through the exhaust passages 41a and 48, so that the, orifice 24. is open for the supply of air to the small tank from the truck tank4 2. If for any cause, as hereafter explained, sumcient pressure should be lost from the small tank I5, so as to materially drop that pressure to a low pressure, such as about ten pounds gauge, then the spring 45 would force the piston member 34 upwardly causing plug 42 to close the exhaust passage 41e. Air pressure entering passage 23 from the truck tank 2 will be exerted through passage 44 against the under side of the enlarged end of piston 34 suihciently to move 34 upwardly so as to raise the valve member 43 from its seat 41; whereupon air from passage 23 may pass by the seat under the piston valve member 21 and close that member against the port or orifice 24. Port or orifice 24 should be suiiciently small so that if one of the lines 6 or 8 from the small tank become uncoupled, air will be lost from the small tank I5 faster than it can be supplied through such port or orifice 24. In such an event, then the valve member 21 is rapidly closed against port 24 to prevent bleeding the truck tank 2 of its air pressure. In this way the breakage of lines E or 8 are prevented from bleeding the air from the truck tank, so the air in that tank will be available to apply the truck brakes when needed.

To the right side of the small tank I5 is clamped a casing member 53 which, together with the wall I1, forms a diaphragm chamber for a diaphragm 54, which forms part of a, relay valve mechanism. The diaphragm 54 is indicated as attached to a follower 55 which is guided into bore 56 of the casing member 53, and the follower 55 has a reduced end dll so as to allow the ow of air from the right of the diaphragm through ports. 6I into the bore 56,. The bore 56 is enlarged to accommodate a valve member 51, which has a packing 58 adapted to form a sealing contact with the shoulder 5,9. The valve member 51 is mounted in a plug 62 threaded to the casing member 53, and is normally urged against its seat by a spring 63 seated in the plug 64. Axial exhaust passages 55 and 66 are provided through the valve member 51 and plug 54,

vand a sealing ring 61 is Provided for the valve member 51. A bore 68 communicates with the bore 56 below the valve seat, and this bore is connected by the line 69 through a valve 10 to the small tank I5. The section 3 of the service line connects with the left side of the diaphragm chamber Where the section 6 of the service line connects with the right side o1" the service line.

By this apparatus it will be seen that the section of the service line 3 merely controls the ow of pressure from the small tank I5 into the seating section of the service line. That is to say,

Whenever valve 3a is operated so as to place pres;- Isure on line 3, the diaphragm 54 is urged to the right closing the follower 55 against valve mem- Yber 51 to close the exhaust passages 65 and 66,

and at the same time forcing the valve member 51 from its seat against the casing 53, and thereby allowing ow of air from the small tank through line 69 through the chamber to the right of the diaphragm and out of line 6. Wheneverl valve 3a is turned to position the exhaust pressure from line 3 the diaphragm is moved to the left closing valve member 51 against-its seat, and

vmoving the follower 55 to open the exhaust lines .so that air is exhausted from the section 6 of the phragm 13, to the upper side of which is connected the service line 6.

From the lower side of the diaphragm lines Il and I2 lead to the brake cylinders. The diaphragm 13 is attached to a follower member 14, which in the position illustrated is engaging a packing on a valve member 15, which valve member is also seated against a seat 16 of the casing. The valve member 15 is a part of a valve means which includes the piston member 11 which is normally urged upwardly, as viewed in Figure 5, by air pressure from the emergency line 8. Between the valve members 15 and the piston 11 there is provided the spring 18 which normally urges these members apart. A rod ,19 is attached to the piston 11 and carries the plug 88, which in another operating position is adapted to close an exhaust port 8I which passes through the valve member 15 to the exhaust port 82. A lateral port 83 is provided for connection with line I8 which leads to the trailer tank. A port 84 is provided through the lower part of the piston member 11 that discharges through the elastic check valve 85.

With such a relay apparatus the air pressure from the small tank I5 is taken through line 8 entering bore 84 and passes through port 83 to line I0 and the truck tank 9, so as to maintain the pressure of the truck tank at least as high .as that of the small tank I5. Whenever air pressure is applied to the service line 6 diaphragm 13 and its follower I4 force valve member 15 downwardly to allow flow of pressure from the trueku tank through ports 83 and through ports 86.to the space underneath diaphragm 13, and hence through lines Il and I2 to the trailer brakes. When the pressure is exhausted from the service line 6 diaphragm 13 moves upwardly closing valve member 15 against its seat 11, and moving the follower 1 4 to uncover the exhaust passages 4I so thatgthe air from thebrake cylinders may be exhausted through lines II and I2 out of exhaust port 82.

With the apparatus thus described, the operations of trailers from trucks is free of dangers which `in the-past have arisenfrom breaking or uncouplingl the emergency or service lines. With this apparatus, if the emergency line 8 is-broken,

so that the pressure in small tank I5 is exhaustfed, this tank is, as previously described, promptly cut off from its communication with the truck tank 2, thereby preventing loss of pressure in the truck tank. Moreover, when the pressure is released from line 8 the piston11 is no longer urged upward, but is moved down by force vof vspring 18 to close plug 80 against the valve member 15, thereby shutting oif the exhaust passages I and 82. Pressure in the trailer tank exerted against the upper side of the largeend of piston 11 further forces this member downwardly to move valve member 15 from its seat 16, so as to cause the pressure in the trailer tank to be applied through lines II and I2 to the trailer brakes. Accordingly, any breakage-of the emergency line results in prompt' application of the trailer brake. v

If service line 3 is broken, there is no eiect on the apparatus until the truck operator attempts to apply the brakes. When this occurs the open.- ing of the relay valve means, including diaphragm 54 (Figure 4), to connect the small tank I5 with the service line 6 merely results in exhausting the small tank I5. This has the effect, as previously described, of immediately disconnecting small tank I5 from the truck tank 2 so as to prevent loss of pressure from the truck tank, so that the truck brakes may operate. Moreover, loss of pressure from small tank I5 removes pressure from the emergency line 8. AsV

a result thereof, the relay valve mechanism of Figure 5 causes prompt action of the trailer tank 9 to the trailer brakes, so that the trailer brakes are set. In this way, both the truck brakes and the trailer brakes become set, not'- withstanding the breakage of the service line, and the fact that such line is broken does not become noticeable to the operator until he attempts to unset the brakes; whereupon he will find it possible to release the trailer brakes by operating valve 3a, and therefore investigate the condition of the service line 5.

From the foregoing description it will be seen that the operation of the system requires a con- .tinuation of pressure within the small tank I5. In order to establish this operating condition, there is provided the charging line 81 (Figure 1), which includes the loading valve 88. Such loading valve is preferably located on the dash of the truck and is operated once after the trailer land its line have been connected to condition the apparatus for operation. The loading valve 88 may be any form of a valve member which may be operated to pass pressure from the truck tank directly into the small tank I5, and in the drawings (Figure 2) as indicated, is formed of a plunger valve means 89, in which the plunger -is provided with sealing rings 9D and 9|. When the loading valve 88 is operated to apply pressure `to small tank I5 pressure is established inline l"i `52 to positionthe valve mechanism of Figure 3 in the position illustrated, wherein the valve fmember 2l is uncovered from the orifice 213 to 'allow future feeding of the small tank l5 from the tank 2 through this oriiice. The loading -valve 89 should then be closed to allow for proper operation of the apparatus. I claim:

1. In a control apparatus for the brakes of a `truck: and trailena service line and an einer- Ageney line extending from the truck to the trailer, means for connection of said lines to a source -of pressure, said means including an orifice of smaller diameter than either or" said lines, said orifice having an inlet side connected to said source of pressure and an outlet side connected to both said service line and said emergency line, said means including a first valve member =movable by pressure to close the iiow of air through said orice and movable on release of said pressure to open the now through said orice, a second valve member controlled by pressure from the outlet side of said orifice to shut oi pressure to said first valve member, and movable on loss of pressure from the outlet side of said orifice to allow application of pressure to said rst valve member, and a pneumatically actuated relay valve in said service line and forming a means for connecting said service line to `said emergency line.

2. In a control apparatus for the brakes or" a truck and trailer, a service line and an einergency line extending from the truck to the trailer, means for connection of said lines to a source `of pressure, said means including an orifice of smaller diameter than either of said lines, said orifice having an inlet side connected to said source of pressure and an outlet side connected to both said service line and said emergency line said means including a iirst valve member movable by pressure to close the ovJ of air through 'saidI orifice and movable on release of said pressure to open the ow through said'orifice, a second valve member controlled` by pressure from the outlet side of said orice to shut ofi pressure -to said first valve member, and movable on loss of pressure from the outlet side of said orifice to 4allow application of pressure to said rst valve member, and a pneumatically actuated relay valve in said service line and forming a means for connecting said service line to said emergency line, a val-ve control line for connecting said second valve member to a source of pressure, said second valve member being responsive to rpressure from said valve control line to also Shut -oi pressure from said first valve member.

3. In a control apparatus for the brakes of a truck and trailer, a service line and an emer- 'gency line extending from the truck to the trailer, means for connection of said lines to a :source of pressure, said means including an orice of smaller capacity than either said service line or emergency line, said orifice having an @inlet side connected to said source of pressure .ing a means for connecting said service line to said emergency line, and a valve control line leading to said diaphragm.

4. In a control apparatus for the brakes of a truck and trailer, a service line and an emergency line extending from the truck to the trailer, means for connection of said lines to a source of pressure, said means including an orice of smaller capacity than either said service line or emergency line, said orifice having an inlet side connected to said source of pressure and an outlet side connected to both said service line and said emergency line said means also including a first valve member movable to control the flow through said orifice, said means including a connection from said source of pressure to said rst valve member to close the same, a second valve member for closing said latter connection, said second valve member being movable to closed'position by pressure from the outlet side of said orifice, s, diaphragm actuated relay valve in said service line and forming a means for connecting said service line to said emergency line, a valve control line leading to said diaphragm, 'and a valve control line from said source to said second valve member for closing the same.

5. In a control apparatus for the brakes of a truck and trailer, a service line and an emergency line extending from the truck to the trailer, a source of pressure on the truck, means connecting said source of pressure to said service line and emergency line, said orifice having an inlet side connected to said source or" pressure and an outlet side connected to both said service line and said emergency line, said means including an oriiice of relatively smaller capacity than the capacity of either the service line or the emergency line, said means including the first valve member movable by pressure from said truck tank to close the flow through said orifice and movable on release of pressure from said truck tank to allow flow through said orifice, a second valve member movable by pressure from the outlet side of said orifice to shut oi the truck tank. from the first valve member, a diaphragm actuated relay valve in said service line, and means for connecting said service line to said emergency line, and a valve control line leading to said diaphragm actuated valve for operatin the same.

trailer, g. source of pressure on the truck, means connecting said source of pressure to said service line and emergency line, said means including an oriiice of relatively .smaller capacity than the capacity of either the service line or the emergency line, said orifice having an inlet side connected to said source of pressure and an outlet side connected to `ooth said service line and said emergency line, said means including the first valve member movable by pressure. from said truck tant: to close the flow through said orice and movable onrelease of pressure from said truck tank to allow flow through said orifice, a second valve member movable by pressure from the outlet side. of said orice to shut oil the tr 'ck tank from the first valve member, a diaphragm actuated relay valve in said service line and providing means for connecting said service line to said emergency line, a valve control line leading to said diaphragm actuated valve for operating thesame, and a separate valve control operating line connecting said truck tank to the second valve member.

7. A control apparatus of the class described, said control apparatus comprising, a body having an inlet for connection to a source of fluid pressure, and an outlet for iiuid under pressure with a passage connecting the inlet and outlet, a valve movable to close said passage and normally maintained in the open position, said body providing a chamber adapted to being alternately vented to the atmosphere and connected to the iluid pressure at said inlet, said valve being adapted to be closed by uid pressure in said chamber, valve means movable alternately into a first position in which said chamber is vented and closed oi from the source of fluid pressure, and into a second position in which said chamber is connected with said fluid pressure, and means operated by fluid pressure to maintain said valve means in said first position, and operated by loss oi fluid pressure to move said valve means to its second position.

8. A control apparatus of the class described, said control apparatus comprising, a body having an inlet for connection to a source of fluid pressure, and an outlet for fluid under pressure with a passage connecting the inlet and outlet, a valve movable to close said passage and normally maintained in the open position, said body providing a chamber adapted to being alternately vented to the atmosphere and connected to the iiuid pressure at said inlet, said valve being adapted to be closed by fluid pressure in said chamber, valve means movable alternately into a rst position in which said chamber is vented while said chamber is closed oii from the source of uid pressure and into a second position in which said vent is closed and said chamber connected with said fluid pressure, means operated by fluid pressure to maintain said Valve means in said first position and operated by loss of iluid pressure to move said valve means to its second position, and means for connecting the outlet to said pressure responsive means whereby the same is operated by loss of pressure at said outlet.

9. A control apparatus of the class described, said control apparatus comprising, a body having an inlet for connection to a source of fluid pressure, and an outlet for uid under pressure with a passage connecting the inlet and outlet, a valve movable to close said passage and normally maintained in the open position, said body providing a chamber adapted to being alternately vented to the atmosphere and connected to the fluid pressure at said inlet, said valve being adapted to be closed by iluid pressure in said chamber, valve means movable alternately into a, rst position in which said chamber is vented while said chamber is closed off from the source of iiuid pressure and into a second position in which said vent is closed and said chamber connected with said uid pressure, means operated by fluid pressure to maintain said valve means in said first position and operated by loss of uid pressure to move said Valve means to its second position, and an oriiice between the inlet and outlet.

10. A control apparatus of the class described, which apparatus comprises, means providing a fluid inlet, a chamber, and a fluid outlet, a valve member movable alternately into two positions, in one position closing communication between the inlet and said chamber, said valve member having an exhaust opening through said Valve member which is opened in said one position, said valve member being movable into such a position wherein the inlet is connected with said chamber and said exhaust opening closed, a valve controlling communication between the inlet and said outlet, said valve being movable to the closed position by pressure in said chamber.

THEODORE HUBBARD AFFLECK.

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